The field of the present disclosure relates generally to turbine assemblies and, more specifically, to a system and method for use in controlling the temperature of compressor intake air of a gas turbine to facilitate improving power output and/or efficiency of the turbine.
Rotary machines, such as gas turbines, are often used to generate power for electric generators. Gas turbines, for example, have a working fluid path which typically includes, in serial-flow relationship, an air intake, a compressor, a combustor, a turbine, and a gas outlet. Compressor and turbine sections include at least one row of circumferentially-spaced rotating buckets or blades positioned within a housing. At least some known turbine engines are used in cogeneration facilities and power plants.
Generally, gas turbines use intake air during normal operation for combustion purposes. Intake air is drawn through a filter house and towards the compressor, wherein the compressor-discharge air is mixed with fuel and ignited in the combustor. Because gas turbines are constant volume, air-breathing engines, many factors and characteristics of intake air, such as the temperature, pressure, and/or humidity of the intake air, may affect the power output and overall efficiency of a gas turbine system. For example, when the temperature of intake air is low, its density increases resulting in a higher mass flow rate flowing through the gas turbine. During such operating conditions, the power output and overall efficiency of the turbine engine is increased.
At least some known turbine assemblies use either evaporative cooling or a cooling coil to reduce the temperature of air being channeled towards the compressor. Evaporative cooling reduces the temperature of air through the evaporation of water and heat is transferred between a working fluid flowing through cooling coils and the intake air. However, the effectiveness of evaporative cooling is a function of the humidity of the ambient air and its effectiveness may be substantially reduced in climates having a high relative humidity. Furthermore, if the cooling coils are installed upstream from the air filters and the intake air is cooled below its dew point, the saturated air mixes with particulates in the intake air. The saturated air and particulate mixture may plug the air filters and trip the gas turbine due to the large pressure drop caused by the plugged filters.